geoprimsField-grade geospatial math

H3 cell inspector

Everything about an cell: center (cellToLatLng), boundary (cellToBoundary), resolution, base cell, pentagon and Class III checks, area, and decimal form.

Go the other way: H3 cell for a point →

40.444865978°

The cell's center is 40.444865978°, -79.981846904°, at resolution 9.

Boundary
LatitudeLongitude
40.446610897-79.982138265
40.445571073-79.984103105
40.443826183-79.983811677
40.443121097-79.981555564
40.444160846-79.979590767
40.445905756-79.979882041
Center longitude
Resolution
Base cell
Pentagon
Class III
Cell area
Provenance
Computed by
indexing.h3.cell-info 1.0.0, core 0.1.0
Model
H3 v4 (h3o 0.11)
Accuracy
Identical to H3 C; coordinates within 1e-12° below 88° latitude, 5e-11° nearer the poles; areas within 6e-15 relative at resolution 0 and 2e-8 at resolution 15, where the 1 m² cell's spherical excess runs out of digits
Notes
None
Cites
Uber Technologies and the H3 contributors, H3: A Hexagonal Hierarchical Geospatial Indexing System (API reference v4); Hydronium Labs, h3o: a Rust implementation of H3

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How we got thisFormula, worked example, sources, and proof

Model: H3 v4 (h3o 0.11)

Accuracy: Identical to H3 C; coordinates within 1e-12° below 88° latitude, 5e-11° nearer the poles; areas within 6e-15 relative at resolution 0 and 2e-8 at resolution 15, where the 1 m² cell's spherical excess runs out of digits

When to use this: Use this when an H3 index arrives and you need to know what it is: the center, the boundary to draw, the resolution, the base cell, whether it is one of the twelve pentagons, whether it is Class III, and the cell's area. It is the first stop when debugging an H3 dataset.

Limitations: The area is that cell's own; H3 cells are not equal-area, and neighbors differ by a few percent. A boundary at a Class III resolution carries extra vertices where cells meet, and a pentagon has no sixth neighbor, which is the case most code built on hexagons forgets.

Worked example: 892a8471487ffff. Source: add-spatial-indexing-and-raster scenario: center about (40.444866°, -79.981847°). It is golden test vector v001, and every build checks the tool still gives its answer within its tolerance.

You enter

H3 cell
892a8471487ffff

You get

Center latitude
40.444865978°
Center longitude
-79.981846904°
Resolution
9
Base cell
21
Pentagon
no
Class III
yes
Cell area
0.105332 km²
Decimal index
617741122143780863

Review: Not yet independently reviewed by a GIS professional.

Last verified: 2026-09-18, when a maintainer last confirmed this tool's sources at the issuer. See the sources ledger.

Status: version 1.0.0, core 0.1.0. See this tool in the verification report.

Changes

Checked against: 23 golden test vectors (download the test vectors, each with its source and tolerance). See how results are checked and every source.

Sources

Terms

H3: H3 hexagonal hierarchical index
A global grid of hexagons (and 12 pentagons) at 16 resolutions, each cell about one-seventh the area of its parent, named by a 15-character index. Source: H3 hexagonal index

H3 — H3 hexagonal hierarchical index

A global grid of hexagons (and 12 pentagons) at 16 resolutions, each cell about one-seventh the area of its parent, named by a 15-character index.

Source: H3 hexagonal index